Questions about C++, a statically typed, free-form, multi-paradigm, compiled, general-purpose programming language.

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95
votes
13answers
15k views

Should we avoid language features that C++ has but Java doesn't to increase maintainability?

Suppose I am limited to use C++ by the environment in the project. Is it good to prevent the use of some language features that C++ has but Java doesn't have (e.g.: multiple inheritance, operator ...
5
votes
4answers
512 views

Is it a good idea to document every assumption in code, even if it goes against the standard of the language?

For instance, would this c++ function be a good idea? void doSomething(not_nullptr<MyType> arg) { // stuff } With not_tullptr being a template wrapper for pointers, that will throw an ...
2
votes
0answers
44 views

How to architect rule matching with multiple conditionals and outcomes

I'm working on allowing my users to create their own ruleset for data that's coming in. All of the data below is sample mock data and not in relation to our product. Example of a rule (there can be ...
-4
votes
2answers
124 views

Repeating a Particular Iteration of For-Loop [closed]

I want to repeat a particular iteration of a for loop twice. The way I am doing it is that I am decrementing the index in that particular iteration. for(int i = 0; i < 100; i++) { ...
3
votes
1answer
311 views

Bad c++ code design? [closed]

This is bothering me a long time. I feel like I am doing mistakes on the code design relative to the performance. I never had any teacher to indicate my mistakes so its hard to me to make it right in ...
1
vote
1answer
166 views

Data structure to use for time-optimized line-vs-grid check?

I am asking here because I feel that this question can be filed under the "algorithm and data structure concepts" category. Background: I have been recently assigned the task to design and develop a ...
0
votes
1answer
69 views

Blocking queue for token based synchronization

I'm currently looking for a good solution for the following use-case in C++ (preferably C++11 or C++14): The program is running a server with a TCP connection. Other clients can connect at any time ...
2
votes
1answer
111 views

What is an appropriate pattern for handling a queue of network events in C++?

I'm writing an application that sends and receives messages over the network and pushes them into a std::deque queue. and I'm looking for the appropriate programming pattern to handle all of the ...
2
votes
2answers
126 views

Abstraction on Iterator Pattern?

Recently, I had the task to implement a research project where I had to read an XML file. XML file contained a list of messages that I had to send to some other system on a specific port. Each message ...
37
votes
9answers
7k views

Explanation on how “Tell, Don't Ask” is considered good OO

This blogpost was posted on Hacker News with several upvotes. Coming from C++, most of these examples seem to go against what I've been taught. Such as example #2: Bad: def ...
21
votes
3answers
6k views

Why is C++ predominant in programming contests and competitions? [closed]

I understand that C++ is a very fast language, but ain't C just as fast, or faster in some cases? Then you might say that C++ has OOP, but the amount of OOP you need for most programming puzzles is ...
0
votes
4answers
376 views

Are there reasons to assign NULL instead of 0 to non-pointer variables?

Assigning variables with values during definition is a good practice. A common practice is to assign variables with 0 and pointers with NULL. int p = NULL; // instead of int p = 0; int *ptr ...
2
votes
2answers
252 views

Error handling in C++

So, in the recent weeks I delved into C++ programming, and I programmed some things in SDL. Doing so, you always have to deal with a lot of (ugly) C++ code, which looks more like C than C++. One thing ...
-1
votes
1answer
85 views

SDL_net how to get the UDP remote address? [closed]

I have a problem with the tcp and udp synchronization. On the server it accepted the tcp connection with the: SDLNet_TCP_Accept(); But now I need to know how to get the remote address of the ...
3
votes
4answers
138 views

Low-level error handling

I am working with some low-level (by that I mean code that can't use C++ exceptions and/or the standard library) code that makes heavy use of classes. Basically, every class contains a bool ...
-1
votes
3answers
184 views

How are expressions evaluated in Turbo C++?

I was reading about casts in c++ and got confused about how are the expressions actually evaluated. Consider the following code in which var is of type int and after the expression var = (var*10)/10 ...
0
votes
3answers
22k views

2 Dimensional Arrays in C++

I started learning arrays in C++ and came over a little side note in the book talking about 2D arrays in breif. I tested it out and i was amazed that it could give the programmer the ability to store ...
4
votes
2answers
141 views

Free-standing function calling a state-changing member function — a bad practice?

Item 23 of Effective C++ (3rd edition) by Scott Meyers is titled: "Prefer non-member non-friend functions to member functions". I understood that the intention of Scott was that, whenever a function ...
5
votes
1answer
115 views

Member vs. free-standing functions with respect to interface uniformity

Item 23 of Effective C++ (3rd edition) by Scott Meyers is titled: "Prefer non-member non-friend functions to member functions". The reason Scott suggests is the increase of encapsulation. So, only the ...
-2
votes
2answers
210 views

How can a software code be made modifiable without being visible to the end user?

I wish to supply a software product with GUI, etc. for operating it. And the software utility is research so the users will want to tweak it to some extent and implement their own preferred algorithms ...
33
votes
9answers
6k views

Is the algorithm more important than the programming language?

During the current (2013) Google Code Jam contest, there was a problem that took C++ and Java people 200+ lines of code as compared to Python people that solved the same problem only using 40 lines of ...
1
vote
3answers
134 views

Do methods Merge and Join make sense for a path class?

I'm writing a path class which currently has a method called Combine which works like the .NET Path.Combine. If an argument is an absolute path (roughly because it begins with \), then it replaces ...
9
votes
1answer
735 views

Object lifetime invariants vs. move semantics

When I learned C++ long ago, it was strongly emphasized to me that part of the point of C++ is that just like loops have "loop-invariants", classes also have invariants associated to the lifetime of ...
0
votes
0answers
94 views

What to unit-test when loading a dll?

I wrote a wrapper class that is using a dll. I have a LoadLibrary() function and have wrapped all the functions the dll exports (to match my error codes). I am not too familiar with unit testing. I ...
7
votes
2answers
294 views

Compile-time checking for NULL initialized std::string

This is sort of the complementary question to How to best protect from 0 passed to std::string parameters?. Basically, I'm trying to figure out whether there is a way to have the compiler warn me if a ...
5
votes
2answers
192 views

C++ class design with invariant

I've been pondering a really basic question about how far to take enforcing a class's invariant. Maybe that's worded badly, so as an example, let's say that I want to write a class which stores a ...
12
votes
11answers
16k views

Avoid Postfix Increment Operator

I've read that I should avoid the postfix increment operator because of performance reasons (in certain cases). But doesn't this affect code readability? In my opinion: for(int i = 0; i < 42; ...
1
vote
1answer
163 views

Function pointers vs. Derived classes

So I have a Signal class and a client class which manages a list of Signal objects. The class provides a bunch of interfaces, one of them is an update()-function. The update()-code is completely ...
5
votes
1answer
157 views

Importing namespaces inside another namespace

I generally like to organize classes I make into modules by using namespaces, and I also don't go more than 2 namespaces deep but it's still painstakingly hard to fully qualify everything. I've ...
2
votes
0answers
56 views

Visual interpolations: independent or linked to object?

I have a class that I use to render GUI elements on the screen, this class has a tree structure (with children, parent, and siblings). I created an additional class which allows me to interpolate some ...
4
votes
1answer
126 views

Which C++ IO interfaces for a complex data source i.e. converter

My question: When you've got a complex converter like, that takes chunks or large result sets out of a database, converts it into a line by line file/resource in the end, should one either design it ...
25
votes
7answers
2k views

Should a C++ program catch all exceptions and prevent exceptions from bubbling up past main()?

I was once advised that a C++ program should ultimately catch all exceptions. The reasoning given at the time was essentially that programs which allow exceptions to bubble up outside of main() enter ...
11
votes
2answers
2k views

Is using Exceptions at the highest level of a program considered bad practice? [duplicate]

I have seen programs using this strategy and I have also seen posts considering this bad practice. However, the posts considering this bad practice have been written in c# or some other programming ...
0
votes
1answer
116 views

How does the base class non-virtual function get called when derived class object is assigned to base class?

#include <iostream> class Base { private: int b_value; public: void my_func() {std::cout << "This is Base's non-virutal my_func()" << std::endl; } virtual void ...
1
vote
1answer
59 views

Managing Opengl projects under Team Foundation Server

I am learning OpenGL/C++ by following a tutorial series on in2gpu. I set up my Project just like the autor did. It is an Empty Visual C++ Project. Inside the project I linked glew and freeglut, the ...
3
votes
1answer
974 views

Template Function: Passing Iterators

I am struggling with making a design choice in the following setup: I am writing (C++) functions which take a pair of iterators (to template containers) and compute a return value of the same type ...
22
votes
8answers
2k views

How did you become a const correctness convert? [closed]

After 15 years of C++, I've still haven't learn to love using const. I understand it's use, but I've never actually been in situation where being const correct would have avoided the problem I was ...
1
vote
2answers
224 views

Preferable design of scope guard in C++

Recently, I come across an issue about the design of scope guard. A scope guard invokes a supplied function object (usually performs cleanup procedures) upon exiting the enclosing scope. The current ...
100
votes
11answers
33k views

What backs up the claim that C++ can be faster than a JVM or CLR with JIT? [closed]

A reoccurring theme on SE I've noticed in many questions is the ongoing argument that C++ is faster and/or more efficient than higher level languages like Java. The counter-argument is that modern JVM ...
45
votes
5answers
9k views

Why are reference-counting smart pointers so popular?

As I can see, smart pointers are used extensively in many real-world C++ projects. Though some kind of smart pointers are obviously beneficial to support RAII and ownership transfers, there is also a ...
1
vote
4answers
909 views

Common header file for C++ and JavaScipt

I have an app that runs a C++ server backend and Javascript on the client. I would like to define certain strings once only, for both pieces of code. For example, I might have a CSS class ...
-1
votes
1answer
71 views

2D Animating in OpenGL [closed]

I am trying to animate a texture in OpenGL. I feel like it should be easy, as I know how to animate in SDL and other libraries but I am having trouble. I have a x,y,w,h that holds the texture ...
12
votes
2answers
4k views

How does C++ handle multiple inheritance with a shared common ancestor?

I'm not a C++ guy, but I'm forced to think about this. Why is multiple inheritance possible in C++, but not in C#? (I know of the diamond problem, but that's not what I'm asking here). How does C++ ...
24
votes
9answers
4k views

What is different between the internal design of Java and C++ that lets C++ have multiple inheritance? [duplicate]

It's drilled into the newbie Java programmers that Java (pre-Java 8) has no multiple class inheritance, and only multiple interface inheritance, because otherwise you run into diamond inheritance ...
2
votes
1answer
110 views

Does it make sense to have a user specified thread limit?

I'm developing a C++14 application and would like to take advantage of the new multithreading features, in particular std::async. I have seen a number of applications which allow the user to specify ...
2
votes
3answers
176 views

Why does the overriding rule of C++ not care about visibility changes?

In C++, it is possible to write an overriding for a base class's method even if the visibility declaration of the two don't match. What are the possible design considerations under the decision of not ...
2
votes
2answers
2k views

Is there any advantage to c-style bit manipulation over std::bitset?

I work almost exclusively in c++11/14, and usually cringe when I see code like this: std::int64_t mArray; mArray |= someMask << 1; This is just an example; I'm talking about bit-wise ...
1
vote
0answers
92 views

Pure abstract classes for input-, output- and bidirectional-pin of microcontroller

I'm writing a real-time operating system for microcontrollers in C++11 - distortos. Currently I'm thinking about a C++ framework for various peripherals. The most basic peripheral which I would like ...
3
votes
2answers
268 views

Is it possible to have pointers recursively point into themselves?

I have been learning C++ recently, and upon reading up on pointers I had a moment of thought. I'm still attempting to grasp the very idea of pointers so excuse me if this doesn't make sense beyond ...
0
votes
2answers
155 views

node.js C++ addons to do all major computations [closed]

A major limitation of node.js is its single threaded execution and the fact that JS is slow with computations. What are the advantages/drawbacks of using C++ to do the application's heavy lifting ...